The perils of South Korea’s booming economy were at the centre of the second day of Pope Francis’ pastoral visit to the country, as he warned lay Catholics not to let “unbridled competition” marginalise the poor.

Francis celebrated Mass for the Feast of the Assumption at the World Cup Stadium in Daejeon in central South Korea on Friday.

He urged Korea’ s Catholics, whom he called “heirs to a noble tradition”, to transform the world in accordance with God’s plan and be a leaven in Korean society.

In his homily he said: “May the Christians of this nation combat the allure of a materialism that stifles authentic spiritual and cultural values and the spirit of unbridled competition which generates selfishness and strife.

“May they also reject inhumane economic models which create new forms of poverty and marginalise workers, and the culture of death … which violates the dignity of every man, woman and child.”

Between the Mass and prayed the midday Angelus he said a prayer for the victims of this year’s Sewol ferry tragedy and their relatives. Many of the bereaved have occupied a square in Seoul where a million Catholics are expected to gather on Saturday for a papal Mass, to demand an independent inquiry into the disaster that killed 476 people.

Francis’ warnings about prosperity echoed the comments he made to Korea’s bishops, whom he met on Thursday afternoon. Since the end of the Korean War in 1953, the southern half of the peninsula has risen from poverty to become the world's thirteenth-largest economy – but Pope Francis warned the country’s bishops that its prosperity posed cultural and spiritual perils.

He told the bishops not to let their country's "prosperous, yet increasingly secularised and materialistic society" distract the Church from its essential duty to evangelise.

"In such circumstances, it is tempting for pastoral ministers to adopt not only effective models of management, planning and organisation drawn from the business world, but also a lifestyle and mentality guided more by worldly criteria of success, and indeed power, than by the criteria which Jesus sets out in the Gospel," Francis said at the headquarters of the bishops' conference.

Later on Friday he was due to meet with young people at the Major Seminary of Daejeon and the Shrine of Solmoe, before travelling back to Seoul ahead of the beatification of 124 Korean martyrs on Saturday.

Top: Francis celebrates Mass at Daejeon's World Cup Stadium, where he also prays for relatives of those who died in the Sewol ferry disaster. Above: He has chosen to be driven around in a modest Kia Soul during his visit. Photos: CNS